Dear Barack, Dear Beyonce, fancy a trip to Oxford?

The Oxford University Debating Union has drawn hundreds of famous or prestigious speakers to take part in its debates over the decades, ranging from prime ministers to Cheeky Girls. This year, they are aiming higher than ever. They have issued an invitation to Barack Obama, who will be in the UK in June for the G8 summit. I am also reliably informed that they have invited Beyonce, who will also in the UK during the summer term, as part of a world tour. But if Obama accepts, I wonder what motion they will ask him to debate, and who will they find to speak against him? Come to that, who would speak against Beyonce?